1. Field of the Invention
This invention relates to the regeneration of living tissues by ingrowth of isolated patient cells into porous implants and the method of using the same in surgical procedures.
2. Description of the Prior Art
Numerous means of attempting to reconstruct human and animal bones and joints which have been damaged through injury or disease such as arthritis, for example, have been known.
It has been known to surgically remove a damaged or diseased joint and replace it with an artificial joint. Among the problems encountered with such procedures are the fact that the joint which is artificial does not possess the natural joint's ability to undergo continuous repair in order to replace effete matrix material and the further fact that it lacks the defense mechanisms against infection. Further, such joints tend to generate toxic wear particles of materials such as metal or plastic.
It has also been known to use transplantation of cadaveric or animal joints. These attempts have generally been unsuccessful as a result of inadequate revascularization of the implanted joints and immunologic rejection of the allografts or zenografts.
U.S. Pat. No. 4,005,495 discloses a ceramic cap bone prosthesis and a method of implantation of the same. U.S. Pat. No. 4,000,525 discloses a ceramic prosthesis said to be suitable for the tibial plateau of a knee joint.
U.S. Pat. No. 2,621,145 discloses a flexible strip of particles of bone held together by a fibrin network positioned on a carrier strip of a material such as cellophane. This is said to encourage rapid regrowth of bone by the body. The material, however, does not have the mechanical strength to permit replacement of a structural portion of the body therewith. It also lacks an isoelastic substrate for effective restitution of biological matrix.
U.S. Pat. No. 3,992,725 describes a method for ingrowth of bone which is positioned immediately adjacent the porous substrate. This disclosure is limited to use in connection with bone tissue which is located immediately adjacent to the porous substrate and discloses a material which would appear to be unsuitable for other tissues of lower modulus of elasticity.
Lacroix, U.S. Pat. No. 3,905,777 discloses invasion of adjacent bone into a porous substrate. The principle thrust of this disclosure is directed toward providing a superficial coating on an otherwise conventional implant.
U.S. Pat. No. 3,849,805 discloses a nonmetallic mesh, bone induction tray which has a plurality of pores and is adapted to contain bone chips. This disclosure also relates to passive ingrowth of bone into an adjacent implant. It does not permit reconstitution of tissue different from an adjacent one. Also, regeneration of bone from chips is undesirable as the bone may form alternatively either fibrous tissue or cartilage or a combination of fibrous tissue, cartilage and bone.
Long U.S. Pat. No. 3,905,047 discloses a bone prosthesis which consists of a ceramic body having a matrix within which a number of discrete particles of a refractory oxide are imbedded and bonded together. The biodegradable nature of the structure can produce potentially toxic degradation products. Also, the high modulus of elasticity makes it vulnerable to undergo brittle fracture.
There remains, therefore, a very real and substantial need for a method of permitting reconstruction of musculoskeletal tissues regardless of whether they are originally present in the region of the implant and in such fashion as to provide resistance to infection, mechanical strength and avoidance of the above-described problems. There is a further need for a product which will effectively accomplish these obejctives.